Spring Cloud微服务使用webSocket的方法

webSocket

webSocket长连接是一种在单个tcp连接上进行全双工通信的协议，允许双向数据推送。一般微服务提供的restful API只是对前端请求做出相应。使用webSocket可以实现后端主动向前端推送消息。

网关配置

spring cloud 的网关组件有zuul和getway

getway

base:
  config:
    nacos:
      nacoshost: localhost
      port: 8848

spring:
  application:
    name: gateway
  main:
    allow-bean-definition-overriding: true
  cloud:
    nacos:
      discovery:
        server-addr: ${base.config.nacos.nacoshost}:${base.config.nacos.port}
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        #  websocket
        - id: CLOUD-WEBSOCKET
          uri: lb:ws://cloud-websocket
          predicates:
            - Path=/cloud-websocket/**
server:
  port: 8888

配置网关的时候注意添加ws协议。

zuul

zuul只能管理http请求，不推荐使用zuul管理websocket连接，推荐直连。

服务端

添加maven依赖

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-websocket</artifactId>
        </dependency>

添加webSocket 配置

@Configuration
@EnableWebSocket
public class WebsocketConfiguration implements WebSocketConfigurer {
    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        // webSocket通道
        // 指定处理器和路径
        registry.addHandler(new WebSocketHandler(), "/websocket")
                // 指定自定义拦截器
                .addInterceptors(new WebSocketInterceptor())
                // 允许跨域
                .setAllowedOrigins("*");
        // sockJs通道
        registry.addHandler(new WebSocketHandler(), "/sock-js")
                .addInterceptors(new WebSocketInterceptor())
                .setAllowedOrigins("*")
                // 开启sockJs支持
                .withSockJS();
    }
}

添加处理器

package com.auexpress.cloud.handler;

import com.alibaba.fastjson.JSONObject;
import org.apache.commons.lang3.StringUtils;
import org.springframework.web.socket.*;
import org.springframework.web.socket.handler.AbstractWebSocketHandler;

import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @Description
 * @ClassName WebSocketHandler
 * @Author HYSong
 * @date 2020.04.14 10:08
 */
public class WebSocketHandler extends AbstractWebSocketHandler {
    /**
     *  存储sessionId和webSocketSession
     *  需要注意的是，webSocketSession没有提供无参构造，不能进行序列化，也就不能通过redis存储
     *  在分布式系统中，要想别的办法实现webSocketSession共享
     */
    private static Map<String, WebSocketSession> sessionMap = new ConcurrentHashMap<>();
    private static Map<String, String> userMap = new ConcurrentHashMap<>();

    /**
     * webSocket连接创建后调用
     */
    @Override
    public void afterConnectionEstablished(WebSocketSession session) {
        // 获取参数
        String user = String.valueOf(session.getAttributes().get("user"));
        userMap.put(user, session.getId());
        sessionMap.put(session.getId(), session);
    }

    /**
     * 接收到消息会调用
     */
    @Override
    public void handleMessage(WebSocketSession session, WebSocketMessage<?> message) throws Exception {
        JSONObject jsonObject = JSONObject.parseObject(message.getPayload().toString());
        String content = jsonObject.getString("content");
        String targetAdminId = jsonObject.getString("targetId");
        if("0".equals(targetAdminId)){
            //  推送给所有人
            userMap.forEach((key,value)->{
                try {
                    this.sendMessage(key,content);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            });
        }else{
            sendMessage("1", content);
        }
    }

    /**
     * 连接出错会调用
     */
    @Override
    public void handleTransportError(WebSocketSession session, Throwable exception) {
        sessionMap.remove(session.getId());
    }

    /**
     * 连接关闭会调用
     */
    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus status) {
        sessionMap.remove(session.getId());
    }

    @Override
    public boolean supportsPartialMessages() {
        return false;
    }

    /**
     * 后端发送消息
     */
    public void sendMessage(String user, String message) throws IOException {
        String sessionId = userMap.get(user);
        if (StringUtils.isEmpty(sessionId)) {
            return;
        }
        WebSocketSession session = sessionMap.get(sessionId);
        if (session == null) {
            return;
        }
        session.sendMessage(new TextMessage(message));
    }
}

添加拦截器

package com.auexpress.cloud.interceptor;

import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.HandshakeInterceptor;

import java.util.Map;

/**
 * @Description
 * @ClassName WebSocketInterceptor
 * @Author HYSong
 * @date 2020.04.14 10:09
 */
public class WebSocketInterceptor implements HandshakeInterceptor {
    /**
     * handler处理前调用,attributes属性最终在WebSocketSession里,
     * 可能通过webSocketSession.getAttributes().get(key值)获得
     */
    @Override
    public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Map<String, Object> attributes) {
        if (request instanceof ServletServerHttpRequest) {
            ServletServerHttpRequest serverHttpRequest = (ServletServerHttpRequest) request;
            // 获取请求路径携带的参数
            String user = serverHttpRequest.getServletRequest().getParameter("user");
            attributes.put("user", user);
            return true;
        } else {
            return false;
        }
    }

    @Override
    public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Exception exception) {

    }
}

到此这篇关于Spring Cloud微服务使用webSocket的方法的文章就介绍到这了,更多相关Spring Cloud使用webSocket内容请搜索我们以前的文章或继续浏览下面的相关文章希望大家以后多多支持我们！